From daaf1b330e56840aefbb9c19a365979c49fce04b Mon Sep 17 00:00:00 2001
From: Marcus Kida <marcus.kida@bearologics.com>
Date: Tue, 25 Jun 2024 10:41:03 +0200
Subject: [PATCH] Implement translation language check (IOS-271)

---
 .../Extension/CoreDataStack/Instance.swift    |  7 ------
 .../MastodonCore/MastodonAuthentication.swift | 24 +++++++++++--------
 .../View/Content/StatusView+ViewModel.swift   |  9 +++++--
 3 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/MastodonSDK/Sources/MastodonCore/Extension/CoreDataStack/Instance.swift b/MastodonSDK/Sources/MastodonCore/Extension/CoreDataStack/Instance.swift
index 006c9881f..5c2dfa5c2 100644
--- a/MastodonSDK/Sources/MastodonCore/Extension/CoreDataStack/Instance.swift
+++ b/MastodonSDK/Sources/MastodonCore/Extension/CoreDataStack/Instance.swift
@@ -48,13 +48,6 @@ extension Instance {
     public var canFollowTags: Bool {
         version?.majorServerVersion(greaterThanOrEquals: 4) ?? false // following Tags is support beginning with Mastodon v4.0.0
     }
-    
-    public var isTranslationEnabled: Bool {
-        if let configuration = configurationV2 {
-            return configuration.translation?.enabled == true
-        }
-        return false
-    }
 }
 
 extension String {
diff --git a/MastodonSDK/Sources/MastodonCore/MastodonAuthentication.swift b/MastodonSDK/Sources/MastodonCore/MastodonAuthentication.swift
index 02416c8d0..7b6eb13d3 100644
--- a/MastodonSDK/Sources/MastodonCore/MastodonAuthentication.swift
+++ b/MastodonSDK/Sources/MastodonCore/MastodonAuthentication.swift
@@ -6,8 +6,18 @@ import MastodonSDK
 
 public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
     public enum InstanceConfiguration: Codable, Hashable {
-        case v1(Mastodon.Entity.Instance, TranslationLanguages)
+        case v1(Mastodon.Entity.Instance)
         case v2(Mastodon.Entity.V2.Instance, TranslationLanguages)
+        
+        public func canTranslateFrom(_ sourceLocale: String, to targetLanguage: String) -> Bool {
+            switch self {
+            case .v1:
+                return false
+            case let .v2(instance, translationLanguages):
+                guard instance.configuration?.translation?.enabled == true else { return false }
+                return translationLanguages[sourceLocale]?.contains(targetLanguage) == true
+            }
+        }
     }
     
     public typealias ID = UUID
@@ -127,13 +137,7 @@ public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
     }
     
     func updating(instanceV1 instance: Mastodon.Entity.Instance) -> Self {
-        guard
-            let instanceConfiguration = self.instanceConfiguration,
-            case let InstanceConfiguration.v1(_, translationLanguages) = instanceConfiguration
-        else {
-            return copy(instanceConfiguration: .v1(instance, [:]))
-        }
-        return copy(instanceConfiguration: .v1(instance, translationLanguages))
+        return copy(instanceConfiguration: .v1(instance))
     }
     
     func updating(instanceV2 instance: Mastodon.Entity.V2.Instance) -> Self {
@@ -148,8 +152,8 @@ public struct MastodonAuthentication: Codable, Hashable, UserIdentifier {
     
     func updating(translationLanguages: TranslationLanguages) -> Self {
         switch self.instanceConfiguration {
-        case .v1(let instance, _):
-            return copy(instanceConfiguration: .v1(instance, translationLanguages))
+        case .v1(let instance):
+            return copy(instanceConfiguration: .v1(instance))
         case .v2(let instance, _):
             return copy(instanceConfiguration: .v2(instance, translationLanguages))
         case .none:
diff --git a/MastodonSDK/Sources/MastodonUI/View/Content/StatusView+ViewModel.swift b/MastodonSDK/Sources/MastodonUI/View/Content/StatusView+ViewModel.swift
index 58bb9df89..2df12c01d 100644
--- a/MastodonSDK/Sources/MastodonUI/View/Content/StatusView+ViewModel.swift
+++ b/MastodonSDK/Sources/MastodonUI/View/Content/StatusView+ViewModel.swift
@@ -696,8 +696,13 @@ extension StatusView.ViewModel {
                 }
 
                 let authentication = authContext.mastodonAuthenticationBox.authentication
-                let instance = authentication.instance(in: context.managedObjectContext)
-                let isTranslationEnabled = instance?.isTranslationEnabled ?? false
+                let isTranslationEnabled: Bool = {
+                    guard let language, let targetLanguage = Bundle.main.preferredLocalizations.first else { return false }
+                    return authentication.instanceConfiguration?.canTranslateFrom(
+                        language,
+                        to: targetLanguage
+                    ) ?? false
+                }()
 
                 authorView.menuButton.menu = UIMenu(children: [
                     UIDeferredMenuElement.uncached({ menuElement in